DESCRIPTION provided by the applicant): We request funds to purchase a BIAcore 3000 for use in a Biosensor Core Facility at the Univ. of Maryland (UM) School of Medicine (SoM). BIAcore uses surface plasmon resonance (SPR) to detect binding of molecules or other materials to a derivatized gold surface. Many features make the 3000 ideal for a core facility. (i) SPR detects binding of a variety of biological materials, be they protein, nucleic acids, lipids, carbohydrates, viruses or cells. (ii) A variety of stable surface chemistries are available from BIAcore, allowing analysis of many different kinds of ligands. (iii) The BIAcore has 4 independently monitored channels, facilitating simultaneous comparisons of control and experimental samples. (iv) Signal-to-noise ratios are high, and precise control of reaction conditions permits reliable monitoring of binding. (v) The BIAcore can accurately measure binding of small molecules. (vi) The hydraulic system minimizes the volume of samples used and facilitates the recovery of bound sample. (vii) The unit is readily automated, permitting unattended use for extended periods of time. The BIAcore 3000 will be used primarily by 5 investigators, 4 at the UM SoM and one at the UM Center for Advanced Research in Biotechnology (CARB). R. Bloch, principal investigator, will utilize BIAcore technology to study interactions between membrane proteins and cytoskeletal proteins of excitable cells. F. Margolis will examine the interactions of olfactory marker protein with proteins identified using a phase display library. E. Weinman will study oligomerization of the epithelial Na,H-exchanger regulatory factor and its binding to other regulatory, cytoskeletal, and transport proteins. J. Fondell will analyze quantitatively the interactions of coactivator proteins with the thyroid hormone-dependent nuclear receptor. R. Mariuzza (CARB), will study binding of antigen to antibody and to the T-cell receptor. Dr. Mariuzza hs extensive experience with an earlier BIAcore model; all four other major users have used SPR technology in studies of protein-protein binding, and two have published their results. The BIAcore 3000 will be housed in a Biosensor Core Facility at the UM SoM and will be directed by Dr. J. Ursitti, an experienced protein chemist and molecular biologist who has already received BIA basics training from BIAcore. The facility will be staffed by a full-time, BIAcore-trained technician. An Internal Advisory committee consisting of Drs. Bloch, Fondell, and Mariuzza will oversee the facility to ensure its smooth functioning, equitable access for all the major users. Newly renovated space has been allocated for the facility by the Department of Physiology, and funds to ensure a smooth start-up as well as ongoing support have been committed by the SoM and the program in Cell and Molecular Biology. We anticipate that this facility will provide its primary users, and ultimately others at the SoM and in the Baltimore area, with state-of-the-art biosensor technology.